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Kalidas Shetty - One of the best experts on this subject based on the ideXlab platform.
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response of oregano origanum vulgare l clonal lines to pseudomonas sp z strain and polydye r 478 and implications for Hyperhydricity prevention in tissue culture
Process Biochemistry, 2002Co-Authors: Sarah Strycharz, Kalidas ShettyAbstract:Abstract Oregano (Origanum vulgare) clonal lines O-1 and O-5 generated via tissue culture were treated with Pseudomonas Z strain and polydye R-478. Pseudomonas Z strain was isolated from naphthalene-contaminated soil and is a known degrader of naphthalene. In this study, Pseudomonas Z strain was investigated for its ability to prevent a plant tissue culture condition known as Hyperhydricity. Many polysaccharide producing Pseudomonas species are capable of preventing this detrimental condition. Previous studies have shown that some Pseudomonas strains enhance the total phenolic content of plants while preventing tissue culture induced Hyperhydricity. Polydye R-478 was used to treat oregano clonal lines O-1 and O-5 in combination with Pseudomonas Z strain to investigate the possibility that a known naphthalene degrader would enhance the plant's tolerance to other aromatic compounds. Pseudomonas Z strain was able to prevent Hyperhydricity in O-1 and O-5 while eliciting a stress response mechanism associated with total phenolic content of the plant. When plants were treated with a combination of Pseudomonas Z strain and polydye R-478, responses varied between the two clonal lines. Clonal line O-1 appears to be a hardier line with a high tolerance to bacterial stress, whereas O-5 is initially affected greatly by bacterial stress, but the shoot cultures that survive are tolerant.
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INFLUENCE OF ACETYL SALICYLIC ACID IN COMBINATION WITH FISH PROTEIN HYDROLYSATES ON Hyperhydricity REDUCTION AND PHENOLIC SYNTHESIS IN OREGANO (ORIGANUM VULGARE) TISSUE CULTURES
Journal of Food Biochemistry, 1999Co-Authors: Nuri Andarwulan, Kalidas ShettyAbstract:Tissue culture-generated shoot-based clonal lines of oregano are being used to investigate the role of proline-linked pentose phosphate pathway in stimulating the phenolic antioxidant, rosmarinic acid (RA) and lignification, which was reported to be linked to guaiacol peroxidase (GPX) activity. One of the problems in oregano tissue culture is Hyperhydricity and modifications of media are being used to control this physiological malformation. This study reports the reduction of Hyperhydricity, stimulation of RA biosynthesis and lignification in oregano clonal line O-1 and O-5 in response to acetyl salicylic acid (ASA), fish protein hydrolysate (FPH, standardized mackerel hydrolysates) and combination of FPH and ASA (FPH/ASA). All treatments reduced Hyperhydricity of both clonal lines compared to control. Following exogenous treatment with ASA and FPH/ASA, enhanced total phenolic content, RA content and concurrently higher levels of GPX activity were observed compared to control and FPH treatments. The concentration of total phenolics and RA as well as GPX activity in O-5 clonal line was higher than in O-1 clonal line either on day 15 or day 30. Antioxidant activity of the phenolic extracts of all cultures was high on day 30 compared to day 15 and FPH/ASA treatment had the highest activity on both days. The concentration of chlorophyll in O-1 was higher than in 0–5 and the concentration in both lines were similar in response to respective treatments. The stimulation of RA synthesis in response to ASA and FPH/ASA provided strong clues that ASA can be used as an abiotic elicitor for RA stimulation and mobilization of proline and/or glutamic acid in FPH and this may be linked to stimulation of the pentose phosphate pathway, driving key precursor metabolites towards shikimate and phenylpropanoid pathways. RA-stimulating compounds also enhanced total phenolics and hardened stem tissues, which correlated with higher GPX activity, indicating possible lignification due to polymerization of phenolic metabolites. This research also provides strategies to prevent Hyperhydricity in tissue culture by ASA and combination of FPH/ASA and these were linked to lignification, high levels of total phenolics and RA. This improvement is important for efficiency and quality of in vitro plant tissue propagation and outdoor transplanting of elite phenolic antioxidant-producing oregano cultures. This research also provides insight into regulation of rosmarinic acid, a phenolic antioxidant relevant for food preservative applications.
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Prevention of Hyperhydricity in oregano shoot cultures is sustained through multiple subcultures by selected polysaccharide-producing soil bacteria without re-inoculation
Applied Microbiology and Biotechnology, 1998Co-Authors: K. Ueno, Kalidas ShettyAbstract:Previous studies from our laboratory showed that several non-specific, polysaccharide-producing soil bacteria could be effectively used to prevent Hyperhydricity. In this study, prevention of Hyperhydricity of shoot cultures of oregano clonal line O-1 was investigated over multiple subculture cycles without re-inoculation of shoots. Results clearly indicate that Hyperhydricity was prevented in oregano shoot cultures over eight subculture cycles without any re-inoculation after the initial inoculation with several polysaccharide-producing bacteria in the first cycle. Hyperhydricity-related parameters of subculture cycles 7 and 8, reported in this manuscript, showed that the water content was significantly reduced in response to all bacteria tested. The total phenolics content, on a fresh-weight and dry-weight basis, was stimulated significantly by all bacterial treatments except Pseudomonas stutzeri in the seventh cycle. The chlorophyll content was significantly stimulated in all treatments on a fresh-weight basis in the two subculture cycles. On a dry-weight basis, except for P. stutzeri, the bacterial species tested induced significant increases in chlorophyll content. Plant growth in response to all bacteria was reduced. In spite of growth reduction, the numbers of shoot nodes available for propagation were not reduced and all the shoot tissues were unhyperhydrated. These results also suggested that prevention of bacteria-mediated Hyperhydricity may be linked to survival of bacteria in the stem, which may be carried through to the next subculture. Acclimation studies showed that bacteria-containing shoots performed better and further strengthened the case for use of non-pathogenic, polysaccharide-producing bacteria for Hyperhydricity control in commercial plant tissue cultures.
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reduced Hyperhydricity and enhanced growth of tissue culture generated raspberry rubus sp clonal lines by pseudomonas sp isolated from oregano
Process Biochemistry, 1998Co-Authors: Susan Cheplick, Kei-ichiro Ueno, Kalidas ShettyAbstract:Abstract Hyperhydricity of vitrification is a physiological malformation that results in excessive hydration, low lignification and reduced mechanical strength of tissue culture-generated plants. This results in poor regeneration of such plants and requires elaborate greenhouse acclimation for outdoor growth. A unique mucoid Pseudomonas sp.; strain F that prevented Hyperhydricity in tissue culture-generated oregano ( Origanum vulgare ) shoot clones was recently isolated in this laboratory. Based on this study we have now tested Hyperhydricity prevention in four commercial clonal lines of raspberry ( Rubus sp.; CDH-92; GEL-20; Heritage; JCR-FL) by bacteria ( Pseudomonas sp.; F strain). Acclimation was enhanced in CDH-92, GEL-20 and to a lesser extent in JCR-FL. Such bacteria-treated clones adapted easily to outdoor or greenhouse conditions. Thirty days after the initial Pseudomonas inoculation (first cycle), clonal lines GEL-20 and Heritage had reduced water content. All four clonal lines were subcultured without re-inoculation over five 30-day cycles carrying the Pseudomonas inoculation from the first cycle. At the end of these five 30-day cycles, the water contents of all clonal lines were significantly lower. After 2.5 months of performing the initial inoculation and prior to the acclimation testing stage, all treated clonal lines except CDH-92 had higher levels of total phenolics compounds and chlorophyll. These results further confirm the role of non-specific plant or rhizosphere-associated, polysaccharide—producing bacteria, in imparting enhanced vigor and stress tolerance in tissue culture-generated plants. This information can be used for rapid acclimation of economically important, tissue culture-generated plant clones to outdoor environments.
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Control of Hyperhydricity in Anise (Pimpinella anisum) Tissue Culture by Pseudomonas spp.
Journal of Herbs Spices & Medicinal Plants, 1998Co-Authors: John S. Bela, Kei-ichiro Ueno, Kalidas ShettyAbstract:ABSTRACT An interaction between anise (Pimpinella anisum) and Pseudomonas offers a simple system to study the physiological and biochemical mechanisms underlying Hyperhydricity, the physiological abnormality associated with in vitro culture of many plant species. Hyperhydricity presents difficulties in regenerating clonal plants, including herbs like anise and oregano, through tissue culture. The use of an oregano-microbe interaction to prevent the physiological malformations associated with Hyperhydricity, was recently reported by our laboratory. In this report, the ability of Pseudomonas spp. originally isolated from an in vitro clonal line of oregano to prevent Hyperhydricity in anise shoot cultures was studied through observations of morphological adjustments and physiological variations in water, chlorophyll, and phenolic content. The Pseudomonas spp. elicited chlorophyll and phenolic production with substantial implications for enhancing the micro-propagation efficiency of many economically importan...
Mariem Lotfi - One of the best experts on this subject based on the ideXlab platform.
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Effects of meta–topolin derivatives and temporary immersion on Hyperhydricity and in vitro shoot proliferation in Pyrus communis
Plant Cell Tissue and Organ Culture (PCTOC), 2020Co-Authors: Mariem Lotfi, Chokri Bayoudh, Stefaan Werbrouck, Messaoud MarsAbstract:Methoxy topoline-riboside (Me m TR) and meta-topoline-riboside ( m TR) were used as alternatives to benzyladenine to prevent Hyperhydricity during the micropropagation of pears in a new temporary immersion system. These cytokinins also increased the number of good quality shoots, characterized by large leaves and longer shoots. Although micropropagation in temporary immersion systems might increase plant growth and multiplication, it can also cause specific problems such as Hyperhydricity and losses by contamination. A new commercial temporary immersion bioreactor, SETIS™, was used to micropropagate two Tunisian pear cultivars, ‘Arbi’ and ‘Mahdia 6’. The latter cultivar was endogenously contaminated by Sphingomonas . Hyperhydricity was inevitable when 5 µM benzyladenine was applied. However, the symptoms could be reduced by lowering the immersion frequency to 3 times per day. Applying 5 µM meta –Methoxy topolin riboside (Me m TR) or meta –Topolin riboside ( m TR) completely inhibited hyperhydric shoot formation. Moreover, the addition of Plant Preservative Mixture was effective to control Sphingomonas and allowed the plants to proliferate. For both pear cultivars, the highest number of shoots per explant was induced by 5 µM Me m TR, whereas the highest leaf area was obtained with 5 µM m TR. The longest shoots were obtained with 5 µM m TR for ‘Arbi’ and 5 µM Me m TR for ‘Mahdia 6’.
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effects of meta topolin derivatives and temporary immersion on Hyperhydricity and in vitro shoot proliferation in pyrus communis
Plant Cell Tissue and Organ Culture, 2020Co-Authors: Mariem Lotfi, Chokri Bayoudh, Stefaan Werbrouck, Messaoud MarsAbstract:Although micropropagation in temporary immersion systems might increase plant growth and multiplication, it can also cause specific problems such as Hyperhydricity and losses by contamination. A new commercial temporary immersion bioreactor, SETIS™, was used to micropropagate two Tunisian pear cultivars, ‘Arbi’ and ‘Mahdia 6’. The latter cultivar was endogenously contaminated by Sphingomonas. Hyperhydricity was inevitable when 5 µM benzyladenine was applied. However, the symptoms could be reduced by lowering the immersion frequency to 3 times per day. Applying 5 µM meta–Methoxy topolin riboside (MemTR) or meta–Topolin riboside (mTR) completely inhibited hyperhydric shoot formation. Moreover, the addition of Plant Preservative Mixture was effective to control Sphingomonas and allowed the plants to proliferate. For both pear cultivars, the highest number of shoots per explant was induced by 5 µM MemTR, whereas the highest leaf area was obtained with 5 µM mTR. The longest shoots were obtained with 5 µM mTR for ‘Arbi’ and 5 µM MemTR for ‘Mahdia 6’. Methoxy topoline-riboside (MemTR) and meta-topoline-riboside (mTR) were used as alternatives to benzyladenine to prevent Hyperhydricity during the micropropagation of pears in a new temporary immersion system. These cytokinins also increased the number of good quality shoots, characterized by large leaves and longer shoots.
Messaoud Mars - One of the best experts on this subject based on the ideXlab platform.
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Effects of meta–topolin derivatives and temporary immersion on Hyperhydricity and in vitro shoot proliferation in Pyrus communis
Plant Cell Tissue and Organ Culture (PCTOC), 2020Co-Authors: Mariem Lotfi, Chokri Bayoudh, Stefaan Werbrouck, Messaoud MarsAbstract:Methoxy topoline-riboside (Me m TR) and meta-topoline-riboside ( m TR) were used as alternatives to benzyladenine to prevent Hyperhydricity during the micropropagation of pears in a new temporary immersion system. These cytokinins also increased the number of good quality shoots, characterized by large leaves and longer shoots. Although micropropagation in temporary immersion systems might increase plant growth and multiplication, it can also cause specific problems such as Hyperhydricity and losses by contamination. A new commercial temporary immersion bioreactor, SETIS™, was used to micropropagate two Tunisian pear cultivars, ‘Arbi’ and ‘Mahdia 6’. The latter cultivar was endogenously contaminated by Sphingomonas . Hyperhydricity was inevitable when 5 µM benzyladenine was applied. However, the symptoms could be reduced by lowering the immersion frequency to 3 times per day. Applying 5 µM meta –Methoxy topolin riboside (Me m TR) or meta –Topolin riboside ( m TR) completely inhibited hyperhydric shoot formation. Moreover, the addition of Plant Preservative Mixture was effective to control Sphingomonas and allowed the plants to proliferate. For both pear cultivars, the highest number of shoots per explant was induced by 5 µM Me m TR, whereas the highest leaf area was obtained with 5 µM m TR. The longest shoots were obtained with 5 µM m TR for ‘Arbi’ and 5 µM Me m TR for ‘Mahdia 6’.
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effects of meta topolin derivatives and temporary immersion on Hyperhydricity and in vitro shoot proliferation in pyrus communis
Plant Cell Tissue and Organ Culture, 2020Co-Authors: Mariem Lotfi, Chokri Bayoudh, Stefaan Werbrouck, Messaoud MarsAbstract:Although micropropagation in temporary immersion systems might increase plant growth and multiplication, it can also cause specific problems such as Hyperhydricity and losses by contamination. A new commercial temporary immersion bioreactor, SETIS™, was used to micropropagate two Tunisian pear cultivars, ‘Arbi’ and ‘Mahdia 6’. The latter cultivar was endogenously contaminated by Sphingomonas. Hyperhydricity was inevitable when 5 µM benzyladenine was applied. However, the symptoms could be reduced by lowering the immersion frequency to 3 times per day. Applying 5 µM meta–Methoxy topolin riboside (MemTR) or meta–Topolin riboside (mTR) completely inhibited hyperhydric shoot formation. Moreover, the addition of Plant Preservative Mixture was effective to control Sphingomonas and allowed the plants to proliferate. For both pear cultivars, the highest number of shoots per explant was induced by 5 µM MemTR, whereas the highest leaf area was obtained with 5 µM mTR. The longest shoots were obtained with 5 µM mTR for ‘Arbi’ and 5 µM MemTR for ‘Mahdia 6’. Methoxy topoline-riboside (MemTR) and meta-topoline-riboside (mTR) were used as alternatives to benzyladenine to prevent Hyperhydricity during the micropropagation of pears in a new temporary immersion system. These cytokinins also increased the number of good quality shoots, characterized by large leaves and longer shoots.
Johannes Van Staden - One of the best experts on this subject based on the ideXlab platform.
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Influence of gelling agent and cytokinins on the control of Hyperhydricity in Aloe polyphylla
Plant Cell Tissue and Organ Culture, 2011Co-Authors: Mariyana Ivanova, Johannes Van StadenAbstract:Shoot regeneration and occurrence of hyper-hydricity in Aloe polyphylla were greatly affected by the type of gelling agent. The use of gelrite resulted in a sig-nificantly lower multiplication and almost four times higher Hyperhydricity (65%) compared to agar-solidified medium. Gelrite was further selected to evaluate if Hyperhydricity can be overcome by altering the physical properties of the gel, as represented by increasing gelrite concentrations. Four concentrations of gelrite (0, 2.4, 6 and 16 g l -1) were tested in combination with zeatin, N 6 -ben-zyladenine (BA) or thidiazuron (TDZ). Almost all explants grown in liquid media in the presence of cytokinins became hyperhydric and lost their ability to regenerate. The greatest shoot formation was obtained on media with 2.4 g l -1 gelrite and 5 lM zeatin or BA, however hyper-hydricity was very high. Satisfactory reduction in hyper-hydricity was achieved only at 16 g l -1 gelrite, under which conditions the multiplication also decreased. The use of TDZ resulted in very low shoot regeneration and high Hyperhydricity irrespective of the gelrite concentration.
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Natural ventilation effectively reduces Hyperhydricity in shoot cultures of Aloe polyphylla Schönland ex Pillans
Plant Growth Regulation, 2009Co-Authors: Mariyana Ivanova, Johannes Van StadenAbstract:An investigation into the role of ventilation to reduce Hyperhydricity in tissue cultures of Aloe polyphylla Schonland ex Pillans revealed that gaseous exchange between the in-vitro atmosphere and the outside environment is an essential prerequisite for controlling this disorder. In closed culture vessels, Hyperhydricity affected as much as 84% of the newly-formed shoots on media gelled with gelrite. The leaves of hyperhydric shoots had a bright green colour, smooth epidermis and large, open stomata. Gaseous exchange was promoted by using modified lids with a hole covered with polyester or cotton mesh. In ventilated cultures, Hyperhydricity was completely eliminated irrespective of the type of gelling agent used. Natural ventilation was further advantageous for the microplants in terms of leaf chlorophyll content as well as the deposition of epicuticular wax, indicating the onset of mechanisms that regulate water loss from the explants. Although culture ventilation was negatively correlated to the regeneration rate and shoot growth, it has the potential to control the appearance of abnormal phenotypes and can be easily adopted for routine A. polyphylla propagation in vitro.
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Nitrogen source, concentration, and NH4+:NO3− ratio influence shoot regeneration and Hyperhydricity in tissue cultured Aloe polyphylla
Plant Cell Tissue and Organ Culture (PCTOC), 2009Co-Authors: Mariyana Ivanova, Johannes Van StadenAbstract:The role of nitrogen (N) supplied as inorganic ammonium (NH4 +) and nitrate (NO3 −), and organic glutamine on shoot regeneration, incidence of Hyperhydricity and production of good quality shoots in Aloe polyphylla explants was investigated. The omission of total N from the culture medium resulted in low proliferation and hindered shoot growth. Ammonium as the sole source of N depressed shoot regeneration and growth and escalated the frequency of Hyperhydricity to ca. 50%. When NO3 − was used as the sole N source, shoots of good quality were produced and Hyperhydricity was completely eliminated. Overall, the MS N combination was superior to any single N source for proliferation and growth of shoots, suggesting a synergistic effect between NH4 + and NO3 − on shoot regeneration. Moreover, the relative amounts of NH4 + and NO3 − also influenced the parameters tested. The highest regeneration was obtained with NH4 +:NO3 − ratios (mM) of 20:40, 30:30 and 40:20. Decreasing the ratio of NH4 +:NO3 − lowered the incidence of Hyperhydricity. This study also demonstrates the potential of glutamine as the sole source of N, since its application resulted in the production of good quality shoots and almost no Hyperhydricity.
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Effect of ammonium ions and cytokinins on Hyperhydricity and multiplication rate of in vitro regenerated shoots of Aloe polyphylla
Plant Cell Tissue and Organ Culture, 2007Co-Authors: Mariyana Ivanova, Johannes Van StadenAbstract:In search for the optimal culture conditions resulting in a high production of healthy plants and low occurrence of Hyperhydricity in tissue cultured regenerants of Aloe polyphylla, we investigated the relationship between ammonium ions in the medium, applied cytokinins (CKs) and CK concentrations in the induction of Hyperhydricity. Shoots were grown on media with different NH4+ concentrations (10.3, 20.6 and 61.8 mM) and supplemented with N6-benzyladenine (BA), zeatin or thidiazuron (TDZ) at 0, 5 or 15 μM. Elevating the levels of NH4+, in the absence of CKs, could not induce Hyperhydricity. Similarly, very low Hyperhydricity was observed when CKs were added to media containing low NH4+ (10.3 mM). However, in the presence of higher NH4+ concentrations, CKs increased Hyperhydricity in a concentration-dependant manner, suggesting that they were capable of inducing this syndrome only when other factors in the culture system were not optimised. High numbers of healthy looking shoots were produced on media with low NH4+ and low BA or zeatin (5 μM). The use of TDZ resulted in the formation of buds, which did not develop into shoots. Identifying the factors responsible for Hyperhydricity is an important step in the successful use of the micropropagation technique for the conservation of this species.
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Endogenous cytokinins in shoots of Aloe polyphylla cultured in vitro in relation to Hyperhydricity, exogenous cytokinins and gelling agents
Plant Growth Regulation, 2006Co-Authors: Mariyana Ivanova, Ondřej Novák, Miroslav Strnad, Johannes Van StadenAbstract:The process of Hyperhydricity in tissue cultured plants of Aloe polyphylla is affected by both applied cytokinins (CKs) and the type of gelling agent used to solidify the medium. Shoots were grown on media with agar or gelrite and supplemented with different concentrations of N6-benzyladenine (BA) or zeatin (0, 5 and 15 μM). Endogenous CKs were measured in in vitro regenerants after an 8-weeks cycle to examine whether the Hyperhydricity-inducing effect of exogenous CKs and gelling agents is associated with changes in the endogenous CK content. On media with agar a reduction in Hyperhydricity occurred, while the gelrite treatment produced both normal and hyperhydric shoots (HS). The content of endogenous CKs, determined by HPLC-mass spectrometry, in the shoots grown on CK-free media comprised isopentenyladenine-, trans-zeatin- and cis-zeatin-type CKs. The application of exogenous CKs resulted in an increase in the CK content of the shoots. Following application of zeatin, dihydrozeatin-type CKs were also detected in the newly-formed shoots. Application of BA to the media led to a transition from isoprenoid CKs to aromatic CKs in the shoots. Shoots grown on gelrite media contained higher levels of endogenous CKs compared to those on agar media. Total CK content of HS was higher than that of normal shoots grown on the same medium. We suggest that the ability of exogenous CKs and gelrite to induce Hyperhydricity in shoots of Aloe polyphylla is at least partially due to up-regulation of endogenous CK levels. However, Hyperhydricity is a multifactor process in which different factors intervene.
Dennis J. Gray - One of the best experts on this subject based on the ideXlab platform.
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Control of Hyperhydricity of mango somatic embryos
Plant Cell Tissue and Organ Culture, 1995Co-Authors: Mary-joy Monsalud, Helena Mathews, Richard E. Litz, Dennis J. GrayAbstract:Hyperhydricity of immature somatic embryos has been a limiting factor for the development of highly embryogenic suspension cultures of many important mango cultivars. Reversion of Hyperhydricity was achieved in two ways: 1) heart-stage somatic embryos (2–3 mm length) were partially dehydrated under controlled conditions at high relative humidity (RH) for 24–48 h and 2) the gelling agent (Gel-Gro) concentration of the plant growth medium was increased from 2.0 to 6.0 g l-1. Partially dehydrated immature somatic embryos were normal in appearance. Somatic embryos that were partially dehydrated germinated precociously when cultured on maturation medium. Although abscisic acid (ABA) did not reverse Hyperhydricity of primary somatic embryos, ABA did stimulate the reversal of this abnormal pattern of development among secondary embryos. ABA (500 μM) inhibited precocious germination and permitted somatic embryo maturation. Partially dehydrated, immature somatic embryos (4–7 mm long) remained viable for up to 32 days in the absence of maturation medium under high RH.